The human prostate is the site of frequent disorders which result in nodular hyperplasia and adenocarcinoma in a high percentage to lder males. the etiology of prostatic adenocarcinoma is unknown. The plasma membrane plays an important role in a variety of cellular functions which are altered as a result of malignant transformation. Many qualitative and quantitative changes in plasma membrane composition are associated with neoplastic transformation. Very little is known concerning the composition of prostate cell plasma membranes and delineation of these cell surface alterations which accompany prostatic oncogenesis may provide a basis for the diagnosis and treatment of prostatic neoplasia. The recent introduction of the lymphocyte hybridoma technique represents an important new tool which is particularly suited to delineate membrane alterations between normal and transformed cells. Using this technique one can obtain monoclonal antibodies against specific membrane components from a complex antigen mixture such as whole cells. The resulting antibodies can then be used as probes to characterize membrane components which are associated with either the normal or transformed cell type. The objectives of this proposal are to produce monoclonal antibodies specific for human prostate adenocarcinoma cells and utilize these antibodies as probes to identify prostate-specific antigens and characterize prostate adenocarcinoma plasma membrane structure. Monoclonal antibody binding specificity will be determined by radioimmunoassay on established cell culture lines and immunoperoxidase on formalin-fixed prostatic tissue. Identification of the prostate-specific antigens and characterize prostate adenocarcinoma plasma membrane structure. Monoclonal antibody binding specificity will be determined by radioimmunoassay on established cell culture lines and immunoperoxidase on formalin-fixed prostatic tissue. Identification of the prostate-specific antigens involve monoclonal antibody-directed immunoprecipitation of the target antigens and resolution by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Characterization of these antigens and prostate cell plasma membranes will utilize carbohydrate-specific radiolabeling techniques, one- and two-dimensional polyacrylamide gel electrophoresis, and competitive binding assays.